import * as fs from 'fs';

const previous_contents = new Map();

export function write_if_changed(file: string, code: string) {
	if (code !== previous_contents.get(file)) {
		previous_contents.set(file, code);
		fs.writeFileSync(file, code);
		fudge_mtime(file);
	}
}

export function posixify(file: string) {
	return file.replace(/[/\\]/g, '/');
}

export function fudge_mtime(file: string) {
	// need to fudge the mtime so that webpack doesn't go doolally
	const { atime, mtime } = fs.statSync(file);
	fs.utimesSync(
		file,
		new Date(atime.getTime() - 999999),
		new Date(mtime.getTime() - 999999)
	);
}

export const reserved_words = new Set([
	'arguments',
	'await',
	'break',
	'case',
	'catch',
	'class',
	'const',
	'continue',
	'debugger',
	'default',
	'delete',
	'do',
	'else',
	'enum',
	'eval',
	'export',
	'extends',
	'false',
	'finally',
	'for',
	'function',
	'if',
	'implements',
	'import',
	'in',
	'instanceof',
	'interface',
	'let',
	'new',
	'null',
	'package',
	'private',
	'protected',
	'public',
	'return',
	'static',
	'super',
	'switch',
	'this',
	'throw',
	'true',
	'try',
	'typeof',
	'var',
	'void',
	'while',
	'with',
	'yield',
]);